Contaminated Land Remediation - Introduction


The term "contaminated land" is defined in the Environmental Protection Act 1990.

It refers to the presence of polluting substances on a site (usually in the soil) in certain concentrations above background levels, which may cause harm (directly or indirectly) to humans, animals, vegetation or structures.


Sources of Contamination


Numerous land uses have the potential to contaminate sites, some of the more significant are:

Chemical Plant
Gas Works

Causes of Contamination


There are a variety of mechanisms by which contamination may occur, including:

Waste landIron in water
In addition to these causes and sources of contamination, further dispersion of contaminants may occur as a result of soil disturbance and movement, wind dispersal, or leaching and drainage into surface and groundwater. The main emphasis of current policy is on restoring contaminated land so that it can be reused for some beneficial purpose such as housing, public open space, new industry or agriculture. Reclamation of this land is justified by the need to conserve unused land, to protect the countryside and to encourage the regeneration of declining industrial areas and inner cities. The regeneration of inner cities is currently receiving much attention but the problem is not solely confined to urban areas, e.g. former land-based disposal sites are now being redeveloped, many of which are in rural or semi-rural locations.

Legislation


Article 3 of the Treaty establishing the European Community specifically includes a policy in the sphere of the environment (paragraph 1(l)) and Article 174 (previously Article 130r) says that Community policy on the environment shall contribute to the following objectives:

Other EC legislation, such as the Amsterdam Treaty, enshrined the principle that: "Environmental protection requirements must be integrated into the definition and implementation of the Community policies and activities, in particular with a view to promoting sustainable development".
The 1999 EC Directive on the Landfill of Waste has also led to a rethink about current waste management strategies.

In the UK, environmental policies have been largely implemented via the following legislation:

The new UK regime for the identification and remediation of contaminated land came into force on 1 April 2000 under section 57 of the Environmental Protection Act 1990. Under the new regime, local authorities will have a duty to identify contaminated land within their area and, if the land is identified as contaminated, determine whether the land is a "special site", i.e. severely contaminated. Land is identified as "contaminated" under the new regime if:
Those sites identified as "special sites" will be the responsibility of the Environment Agency, while all other sites will be the responsibility of the local authority. Once "contaminated land" or "special sites" have been identified, the owners, occupiers and other appropriate parties will be notified that this is the case. A consultation period of three months will then take place and will usually end with the issuing of a remediation notice which may impose obligations on the recipient to assess the land, undertake works on the land, to clean-up the contamination and monitor the land after it has been remedied.

Risk Management



Risk management may be defined as:

Evaluating alternative actions and selecting among them. This entails consideration of political, social, economic, and engineering information with risk-related information to develop, analyse, and compare options and to select the appropriate response to a potential hazard. The selection process necessarily requires the use of value judgments on such issues as the acceptability of risk and the reasonableness of the costs of risk reduction.
In the contaminated land field, risk assessment provides information to decision makers as to the consequences of possible actions. Important decisions that could use risk estimates include waste treatment/disposal options, remediating contaminated sites, minimizing waste generation, siting new facilities, and developing new products. It should be emphasized that risk estimates are only one type of information used, and contaminated land decisions are often driven by political, social, and economic or other factors.

Another application of risk management in site remediation is the establishment of cleanup standards. The process starts with a numerical definition of acceptable risk and works back to the level of contamination that will produce the acceptable risk level.

Thus, environmentally sound legislation concerning pollution and sustainability as well as pressure on the land resources that are available in the UK has led to a growing industry in site remediation. The aims of this industry are to reduce the amount of risk to humans and the environment that a contaminated site poses, such that it is deemed safe to be used for a number of defined purposes. There are various remedial techniques and methods available to a contaminated land developer.